Balloon perfusion catheter

ABSTRACT

Catheter for use in catheter procedures. The catheter includes a balloon carried at the distal end of an elongate shaft. A mechanism is included for providing a generally open perfusion passage while the balloon is in an inflated state. The perfusion passage provides both branch and distal perfusion. A mechanism is secured against the balloon for supporting the perfusion passage while the balloon is in an inflated state, and a mechanism is provided for retaining the balloon shape under pressure.

This is a continuation of application Ser. No. 08/520,755 filed on Aug.29, 1995 now U.S. Pat. No. 5,556,382.

BACKGROUND OF THE INVENTION

The present invention relates to the field of angioplasty. Inparticular, the present invention relates to an intravascular perfusioncatheter. The perfusion catheter is a dilatation balloon catheter, whichprovides both distal and side branch perfusion, and may be used forrapid exchange procedures.

Angioplasty procedures have gained wide acceptance in recent years as anefficient and effective method for treating certain types of vasculardiseases. In particular, angioplasty is widely used for treatment ofstenosis in the coronary arteries, although it is also used fortreatment of stenosis in other parts of the vascular system.

The most widely used form of angioplasty makes use of a dilatationballoon catheter to treat a stenosis, and thereby reestablish anacceptable blood flow through the artery. The dilatation catheterincludes an elongated tubular shaft and an inflatable balloon carried ata distal end of the shaft.

In operation, the catheter is inserted through a hollow guide catheter,which has been previously introduced into a patient's vascular systemfrom a location remote from the heart (e.g., femoral artery). Theproximal end of the guide catheter remains outside of the patient, whilethe distal end of the guide catheter is positioned at the ostium of thecoronary artery to be dilatated.

A dilatation catheter is introduced into the proximal end of the guidecatheter and advanced to the distal end of the guide catheter. Then,using fluoroscopy, the physician guides the dilatation catheter theremaining distance through the vascular system until the balloon ispositioned across the stenosis therein. The balloon is inflated bysupplying fluid under pressure through an inflation lumen in thecatheter to the balloon.

The inflation of the balloon causes a widening of the lumen of theartery to reestablish acceptable blood flow through the artery. After ashort inflation period, the balloon is deflated and the arterialtreatment is evaluated to determine whether the procedure hasreestablished an acceptable blood flow. If necessary, the dilatationprocedure is repeated with the catheter balloon being reinflated.

Dilatation balloon catheters occlude blood flow while the balloon isexpanded in the coronary artery. The balloon may be expanded for only ashort inflation period, since occlusion of the coronary artery forextended periods may result in damage to portions of the heart whichshould receive blood from the occluded artery. Lack of blood circulationcan lead to myocardial ischemia and angina, or anemic necrosis oftissues already stressed by the previously reduced level of blood flow.

One solution to allow extended inflation periods for complete treatmentof the stenosis is the use of perfusion catheters. Perfusion cathetersprovide a path for blood to flow past the balloon, while the balloon isin an inflated state within the blood vessel. Thus, blood can besupplied to areas downstream of the inflated balloon during treatment ofthe stenosed artery.

U.S. Pat. No. 4,581,017 to Sahota suggests a perfusion catheter whichincludes a tubular shaft having a guide wire and perfusion lumen, and aninflation lumen. A dilatation balloon which communicates with theinflation lumen is carried at the distal end of the shaft. The tubularshaft includes at least one opening on the proximal side of the balloonand at least one opening on the distal side of the balloon, whichcommunicate with the guide wire and perfusion lumen. When the balloon isinflated, blood may flow past the balloon by flowing through theproximal opening, through the guide wire and perfusion lumen, and outthe distal opening.

Other perfusion catheters include a separate conduit for allowing bloodto flow past the inflated balloon, such as is suggested in U.S. Pat.Nos. 4,983,167 and 5,147,377 to Sahota, U.S. Pat. No. 5,078,685 toColliver, and U.S. Pat. No. 5,383,890 to Miraki et al. The perfusionconduits extend either through the dilatation balloon or along theoutside of the dilatation balloon.

It is desirable to provide a dilatation balloon catheter which allowsrelatively high volumes of blood to flow past the balloon to a locationdistal of the balloon while the balloon is in an inflated state.Additionally, it is desirable to provide a perfusion catheter whichallows blood flow to both distal and branch arteries. It is alsodesirable to provide a perfusion catheter which is low profile, and maybe used in rapid exchange procedures.

SUMMARY OF THE INVENTION

The present invention is a perfusion balloon catheter for use incatheter procedures. In particular, the present invention includes aperfusion balloon catheter which provides both side branch and distalperfusion while the balloon is in an inflated state.

In one preferred embodiment, the present invention is a balloonperfusion catheter including an elongate shaft having a proximal end anda distal end, and an inflation lumen extending from the proximal end tothe distal end. A balloon is carried by the shaft at the distal end. Theballoon is in fluid communication with the inflation lumen. A structureis included for providing a generally open perfusion passage while theballoon is in an inflated state.

The structure for providing a generally open perfusion passage mayinclude a support member secured against the balloon for supporting thepassage while the balloon is in an inflated state. In alternativeembodiments, the support member may be generally C-shaped, U-shaped,serpentine shaped, or coil shaped.

The perfusion passage may be located exterior to the balloon.Additionally, a retaining member may be included for retaining theballoon shape under pressure. The retaining member may include aperfusion wrap secured around the balloon. The perfusion wrap allowsside branch perfusion. In one embodiment, the perfusion wrap is formedof strands. In another embodiment, the wrap includes a thin sleevehaving side holes for side branch perfusion.

In yet another embodiment, the present invention includes a catheter foruse in catheter procedures. The catheter includes an elongate shafthaving a proximal end and a distal end and an inflation lumen extendingtherethrough. A balloon is carried by the shaft at the distal end. Theballoon is in fluid communication with the inflation lumen. A mechanismis included for providing a generally open perfusion passage while theballoon is in an inflated state, including a perfusion wrap forretaining the shape of the balloon when the balloon is in an inflatedstate.

The perfusion passage may provide both side branch and distal perfusion.The perfusion passage may further include a guide wire passage.

Additionally, the mechanism for providing a generally open perfusionpassage may include a generally open support member carried adjacent theballoon for supporting the passage while the balloon is in an inflatedstate. The support member may include the means for slidably retaining aguide wire.

In yet another embodiment, the present invention includes a method ofproviding a perfusion passage during a catheter procedure. A shaft isprovided having a balloon carried at a distal end, including aninflation lumen extending therethrough in communication with theballoon. The balloon is inflated within an artery. Blood flows past theballoon through a perfusion passage to side and distal branches whilethe balloon is in an inflated state. A generally open support member isincluded which is carried by the balloon.

The shape of the balloon is retained with a balloon wrap duringinflation of the balloon. The balloon wrap may be formed of strands.Additionally, a guide wire may be passed through the perfusion passage.The guide wire may be passed through the support member. In oneembodiment, the support member is of a generally serpentine shape.

The balloon catheter of the present invention provides a perfusionpassage allowing both distal and branch perfusion during inflation ofthe catheter balloon. The balloon catheter of the present inventionallows large amounts of blood to pass through the perfusion passage.Additionally, the present invention maintains the shape of the balloonduring inflation of the balloon.

The present invention may be used in a low profile balloon cathetersystem for dilating a stenosis. Additionally, a guide wire may bemovably received through the perfusion passage for use in rapid exchangeprocedures, or for maintaining a path across the stenosis duringcatheter procedures.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be further described with reference to accompanyingdrawings where like numbers refer to like parts throughout the severalviews, and wherein:

FIG. 1 is a perspective view of a catheter in accordance with thepresent invention;

FIG. 2 is a top view of the catheter taken at area A of FIG. 1;

FIG. 2A is a longitudinal expanded cross-sectional view taken along line2A--2A of FIG. 2;

FIG. 3 is a cross-sectional view of the catheter taken along line 3--3of FIG. 2;

FIG. 4 is a cross-sectional view of the catheter taken along line 4--4of FIG. 2;

FIG. 5 is a cross-sectional view of the catheter taken along line 5--5of FIG. 2;

FIG. 6 is a perspective view of a balloon support member in accordancewith the present invention; and

FIG. 7 is a perspective view of a balloon wrap in accordance with thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 illustrates an intraluminal catheter of the present invention foruse as an angioplasty dilatation balloon catheter generally at 20. Thecatheter 20 includes a shaft 22 having a proximal end 24 and a distalend 26. An inflation lumen 28 extends longitudinally through the shaft22 from the proximal end 24 to the distal end 26 (shown in FIG. 3).Operably connected to the proximal end 24 of the shaft 22 is a hub orluer assembly 32 which communicates with the inflation lumen 28. Theluer assembly 32 provides for connection to other catheter devices, suchas a Y adapter, during a catheterization procedure.

In one embodiment, shaft 22 can be similar to the shaft disclosed inU.S. Pat. No. 5,425,711 to Ressemann et al., which is hereinincorporated by reference. In general, Ressemann et al. discloses ashaft formed from an elongated metallic tube having an inflatableballoon at its distal end. A plastic tube connects a distal end of themetallic tube to the proximal end of the balloon. The metallic andplastic tubes thus define a lumen for providing inflation pressure tothe balloon. The metallic tube and core member provide the necessarypushability for the catheter to permit its highly controlled advancementalong a guide wire, and for tracking the guide wire through tortiousvascular lumens.

Referring to FIG. 2, which is an enlarged top view of area A shown inFIG. 1, the distal end 26 of the balloon catheter 20 is shown. Carriedat a distal end of the shaft 22 is a dilatation balloon system 34indicated within dashed area A. The dilatation balloon system 34includes a dilatation balloon 36 having a proximal end 38 and a distalend 40. Referring to FIG. 2A, a cross-sectional side view of theproximal end 38 of the dilatation balloon system 34 is shown.

Located at the proximal end 38 of dilatation balloon 36 is guide wireconduit 42 having an opening 44. Guide wire conduit 42 is secured toshaft 22 and extends to the proximal end 38 of dilatation balloon 36.Guide wire 46 passes through guide wire conduit 42 for advancing theballoon catheter 20 over the guide wire 46. In one embodiment, the guidewire conduit 42 is formed of a stainless steel hypotube.

Referring also to FIG. 3, which is a cross-sectional view of theproximal end 38, inflation lumen 28 is in fluid communication withdilatation balloon 36 for inflation of dilatation balloon 36 during anangioplasty procedure. Core member 30 extends through inflation lumen28.

Referring to FIG. 4, balloon 36 includes an interior 50 in fluidcommunication with the inflation lumen 28 of shaft 22. The balloon 36 isformed of suitable balloon material as known in the art. In onepreferred embodiment, the suitable balloon material is a polyolefinwhich has been treated by electron beam cross linking. A suitablepolyolefin is available from E. I. DuPont de Moores Company ofWilmington, Del. under the tradename SURLYN® (8527) Ionomer. Balloon 36may also be coated with a lubricous material, such as a silicone orhydrophilic lubricant. Balloon length varies depending upon the desiredsize of the dilatation catheter, with typical balloon lengths 10 to 40ml. A typical preferred dilatation diameter for the balloon is 1.5 to 4mm.

Core member 30 extends through the balloon 36 interior 50 withininflation lumen 28. A distal neck 52 located at the distal end 40 issealably connected to a distal member 48 by a suitable adhesive andsealing material such as LOCKTIGHT PRISM 405, a cyanoacrylate availablefrom Locktight Corp. of Newington, Conn., or TRADEBOND 2315D, an epoxyavailable from Tra-Con, Inc. of Medford, Mass.

Core member 30 is secured to the distal end member 40 of dilatationballoon 36 at distal member 48. A radiopaque marker band may be locatedalong core member 30, centered within dilatation balloon 36 to aid inpositioning dilatation balloon 36 across the stenosis during theangioplasty procedure.

Referring to FIG. 5, a cross section of the distal member 48 is shown.As previously stated, core member 30 terminates at distal member 48 andis secured to distal member 48 by an adhesive. Additionally, guide wire46 extends through distal member 48 through an opening 49.

A perfusion passage 54 extends longitudinally along the exterior ofdilatation balloon 36. The perfusion passage 54 allows a relativelylarge volume of blood to flow past an inflated balloon 36 for perfusionof both side branch and distal coronary arteries.

Perfusion passage 54 is defined by the exterior of balloon 36. Perfusionpassage 54 includes proximal opening 56, distal opening 58, and branchopening 60 along the entire longitudinal length of balloon 36. A supportmember 62 is secured to the exterior 64 of balloon 36 for defining andmaintaining the perfusion passage 54 during inflation of balloon 36.

Support member 62 is of a generally C-shaped or U-shaped cross section,having an opening toward branch opening 60 along the longitudinal lengthof dilation balloon 36. In one preferred embodiment, support member 62is secured to the external balloon surface by a urethane. The proximalend of support member 62 encircles and is bonded to guide wire conduit42, indicated at 63. The distal end of support member 62 is bonded todistal member 48, indicated at 65.

In one preferred embodiment shown in FIG. 6, support member 62 isgenerally serpentine shaped and formed of wire. The serpentine shapedwire 64 extends from the proximal opening 56 through the perfusionpassage 54 to the distal opening 58. The generally serpentine shapedwire 64 is formed having a generally U-shaped or C-shaped bend in themiddle corresponding to the desired cross section of the perfusionpassage. Alternatively, it is recognized that the perfusion passage 54support member 62 may take on other shapes within the scope of thisinvention, such as a spiral-shaped wire. Support member 62 is formed ofa shape that is generally open, allowing both branch and distalperfusion through the perfusion passage 54.

The support member 62 provides support to the perfusion passage 54during inflation of balloon 36 without undue rigidity that a tubular orconduit member has. As the balloon 36 is inflated, the support member 62keeps balloon 36 from collapsing the perfusion passage 54.

Additionally, guide wire 46 can extend through perfusion passage 54. Asshown in FIG. 6, the serpentine wire 64 includes loop members 68 forslidably retaining guide wire 46. In one preferred embodiment, thesupport member 62 is coated with a lubricous polymer for ease ofmovement of guide wire 46 relative to members 68.

A wrap 70 is located around balloon 36 to maintain the desired balloonshape during inflation of the balloon. Wrap 70 is a generally flexiblemember, which is secured to the balloon 36 exterior surface, andcollapses with the balloon 36 when balloon 36 is in a deflated state.Although in one preferred embodiment, wrap 70 crosses the branch opening60 of balloon 36, wrap 70 is generally open to allow branch perfusion.

In one preferred embodiment, wrap 70 is a balloon shape retainer formedof braided strands. The braided strands are preferably a high-strengthpolymer fiber, such as polyamide, polyester, or aramid. The strands 72are secured to the balloon 36 exterior surface by coating the entirestranded wrap 70 with urethane or by using an adhesive such as epoxy atthe balloon 36 proximal end 38 and distal end 40. Although the urethanemay cover the entire wrap 70 strands 72, the urethane does not close theopenings between the strands 72, nor otherwise interfere with sidebranch perfusion.

In an alternative embodiment, the wrap 70 includes strands 72 which arespiral wrapped around the balloon, the spiral wrap extending from theballoon proximal end 38 to the balloon distal end 40. The strands 72 aresecured to the balloon 36 using an adhesive at the proximal end 38 andthe distal end 40. In one preferred embodiment, the adhesive is aurethane adhesive.

Referring to FIG. 7, an alternative embodiment of wrap 70 is shown. Wrap70 includes a relatively thin sleeve 73 having openings 75. Sleeve 73 isformed of a polymeric material. In one preferred embodiment, sleeve 73is secured to balloon 36 by heat bonding the sleeve 73 to the balloon36. Openings 75 allow side branch perfusion of blood.

As balloon 36 is inflated, wrap 70 flexes with the inflated balloon 36retaining the shape of balloon 36 as the balloon forms the perfusionpassage 54 defined by support member 62. Since wrap 70 is generallyopen, wrap 70 does not interfere with side branch perfusion.Additionally, as balloon 76 is deflated, wrap 70 is flexible and recedesfrom its inflated shape retaining position.

Guide wire 46 extends through guide wire conduit 42, perfusion passage54, and distal member 48 allowing the position of guide wire 46 to bemaintained across the stenosed region during positioning and removal ofcatheter 20. Additionally, the passage of guide wire 46 extends throughthe distal end 26 of balloon catheter 20 allowing balloon catheter 20 tobe used for rapid exchange procedures.

In a typical coronary angioplasty procedure, the femoral artery isentered percutaneously and a sheath is inserted into the artery toprovide access to the patient's vascular system. A guide catheter (notshown) is introduced over a guide wire through the previously placedfemoral introducer sheath and advanced up to the aortic arch. The guidecatheter is advanced and maneuvered until a distal end thereof isproperly engaged in the ostium of the coronary artery to be dilatated. AY adapter manifold assembly may be attached to the guide catheter hub atthe proximal end for implementation of therapeutic procedures, such asdye delivery, flushing capabilities, pressure monitoring, and deliveryof the dilatation balloon system.

Once the guide catheter is in place, the guide wire 46 is then alignedin the stenosed artery to a desired position through the stenosis. Theangioplasty dilatation balloon catheter 20 of the present invention isadvanced along the guide wire 46 to position the balloon across thestenosis.

During inflation of the balloon for treatment of the stenosed artery,blood flow is occluded within the artery. Occlusion of a coronary arterycannot be permitted for more than a limited time without incurring riskof damage to portions of the vascular system which receive blood fromthe occluded artery. Even relatively short balloon inflation periodsgive rise to a risk of myocardial ischemia or necrosis of the downstreamtissues stressed by the reduced level of blood flow. Therefore, theballoon 36 is inflated for relatively short periods of time and thendeflated to restore circulation through the artery being treated.

The balloon catheter 20 of the present invention is a perfusion catheterwhich allows blood to flow through the balloon during the period of timethat the balloon is in an inflated state. The dilatation balloon 36 hasa perfusion passage which allows a large volume of blood to flow to bothbranch and distal arterial regions during balloon inflation andtreatment of the stenosis. During the angioplasty procedure, thephysician may need to rotate the balloon to align the side branchperfusion region with the desired side branch. The perfusion passageallows treatment of the stenosed artery for extended periods of time,limiting the serious risk of myocardial ischemia and anemic necrosis oftissues stressed by the reduced level of blood flow and other damage toportions of the heart which should receive blood from the arteryreceiving treatment.

Additionally, the perfusion catheter of the present invention is a lowprofile catheter which allows treatment of stenosed arteries in distalregions of the patient's vascular system. The guide wire extends throughthe perfusion passage for allowing the guide wire to be maintainedacross the stenosed area during catheter exchange procedures.

It will be understood that this disclosure is, in many respects, onlyillustrative. Changes may be made in details, particularly in matters ofshape, size, material, and arrangement of parts, without exceeding thescope of the invention. Accordingly, the scope of the invention is asdefined in the language of the appended claims.

What is claimed is:
 1. In a balloon perfusion catheter including anelongate shaft having a proximal end and a distal end, and an inflationlumen extending from the proximal end to the distal end, the improvementcomprising:a balloon carried by the shaft at the distal end, in fluidcommunication with the inflation lumen; and a perfusion passage formedby the exterior of the balloon having a proximal opening, a distalopening, and a side opening when the balloon is in an inflated state. 2.The catheter of claim 1, wherein the perfusion passage has a maximumwidth that is greater than the width of the side opening.
 3. Thecatheter of claim 1, wherein the perfusion passage is proximate to theinflation lumen.
 4. The catheter of claim 1, wherein the perfusionpassage is located adjacent the inflation lumen.
 5. The catheter ofclaim 4, wherein the inflation lumen is located along a longitudinalcenter axis of the balloon.
 6. The catheter of claim 1, furthercomprising a support member positioned within the perfusion passage forsupporting the perfusion passage during inflation of the balloon.
 7. Thecatheter of claim 6, wherein the support member generally includes aproximal opening, a distal opening, and a side opening.
 8. The catheterof claim 7, wherein the maximum width of the support member is greaterthan the width of the side opening.
 9. The catheter of claim 7, whereinthe support member is a generally tubular shaped member.
 10. Thecatheter of claim 1, further including a shape retaining member forretaining the shape of the balloon when it is in an inflated state. 11.The catheter of claim 10, wherein the shape retaining member allowsfluid to pass therethrough.
 12. The catheter of claim 11, wherein theshape retaining member is a perfusion wrap.
 13. The catheter of claim11, wherein the shape retaining member at least partially covers theside opening of the balloon.
 14. The catheter of claim 10, wherein theshape retaining member includes a support member positioned within theperfusion passage for supporting the perfusion passage during inflationof the balloon.